The goal of this project is to map and identify genes for herditary deafness. Linkage analyses are being conducted in several large pedigrees segregating non-syndromic and syndromic forms of deafness. If linkage to the known syndromic, DFNA (dominant) and DFNB (recessive) loci in large families are excluded, we initiate genome-wide screens. This strategy has allowed us to map new deafness loci such as DFNA20, DFNA27, DFNA28 and DFNA36. The chromosomal map locations of these novel deafness genes are then refined prior to initiating positional cloning strategies to identify the genes responsible for the hearing loss. Recently we have identified genes for DFNB12, DFNA28 and Usher 1D. Additional families with dominant and recessive modes of inheritance with profound congenital or progressive hearing loss are being ascertained with the goal of mapping and cloning additional novel genes that are necessary for hearing and/or maintenace of the auditory system. We are also asscertaining families, mapping loci and identifying genes for Usher syndrome. The defining clinical features of Usher syndrome are hearing loss and progressive retinopathy.